The invention relates to a magnetic valve comprising a valve seat and a closing member movable into a closing direction upon a magnetic field traversing a coil. It is known in such a valve (DE-OS 34 16 465) to separate a hydraulic portion including an inlet opening and a outlet opening, an annular valve seat and closing member, from a magnetic portion spatially. The magnetic portion is arranged above the hydraulic portion, and a magnet armature, which is attracted by a toroidal coil according to control, actuates the valve member via a valve stem. Therefore, in this known valve, it is necessary to change the flow direction of a medium from the valve, usually the cooling liquid of an internal combustion engine, in a twofold manner, since the valve part, with its closing member is arranged in an axial stacked arrangement with the armature of the magnet part and the liquid medium cannot also flow through the magnet part with armature after the valve member moves to its open position. Nevertheless, in this known valve which is suitable for use in a heating device for heating the passenger space of a motor vehicle having a liquid-cooled internal combustion engine, it must be ensured that no corrosion can occur above the hydraulic area, that is, in the magnet part from an air stream. Therefore, the valve stem a has a thoughbore and forms a duct for the cooling medium.
In addition, the known magnetic valve has a rather complicated construction since, to give a numerical example, no fewer than 18 element parts or components are required, and a considerable magnetic circulation and a correspondingly large expenditure of energy are required for controlling the magnet coil due to the transmission of force via the valve stem for switching the valve.